1. Field of the Invention
The present invention relates to a cooking stove comprising heating means, and in particular, to a cooking stove comprising an operation section that indicates an operation of heating means on a top surface of a top plate.
2. Description of the Related Art
A drop-in type cooking stove is conventionally known in which a cooking stove main body 101 is buried in an opening formed in a counter top of a system kitchen as shown in FIG. 6. Operation knobs 103a and 103b are provided on a glass top plate 102 to ignite and extinguish gas burners 100a and 100b and to adjust thermal power; the glass top plate 102 covers a top surface of the cooking stove main body 101 in which gas burners 100a and 100b are accommodated (see, for example, Japanese Utility Model Laid-Open No. 58-186302 (1983)).
Such a cooking stove eliminates the need to form an opening through which an operation section is viewed, in a front surface of the counter top as in the case in which a cooking stove comprising an operation section in a front surface is installed. The cooking stove can be easily installed in the counter top. Further, the gas burners can be ignited and extinguished and thermal power adjusted using the operation knobs 103a and 103b, provided on the top plate 102 and which are thus easy to see. Consequently, a user can operate the cooking stove more easily and effectively.
In the cooking stove shown in FIG. 6, however, the operation knobs 103a and 103b are arranged so as to project from the top surface of the glass top plate 102. Accordingly, the operation knobs 103a and 103b may obstruct cooking. Thus, for example, a detecting section of an electrical-capacitance sensor may be provided on a back surface of the glass top plate 102 as means for operating the gas burners 100a and 100b. On the other hand, a touch switch comprising an operation section may be constructed on a front surface of the glass top plate 102. Further, the top surface of the glass top plate 102 may be made flat.
A thermal power up switch and a thermal power down switch are provided in order to increase and reduce the thermal power of the gas burners 100a and 100b by a plurality of levels; the thermal power up switch is used to give instruction to the appliance to increase the thermal power and the thermal power down switch is used to give instruction to the appliance to reduce the thermal power. The thermal power up switch is configured so that when the user keeps touching the thermal power up switch to keep it on, the thermal power of the gas burner increases continuously by a plurality of levels.
Similarly, the thermal power down switch is configured so that when the user keeps touching the thermal power down switch to keep it on, the thermal power of the gas burner decreases continuously by a plurality of levels.
However, if the thermal power up switch is such a touch switch, it may be kept on when covered with a cooked material boiling over from a pan placed on trivets 104a and 104b or an object falling onto the top plate 102 during cooking.
Further, for example, while the right burner 100b is being used for cooking, when the thermal power up switch is turned on owing to a factor different from the user's operation as described above, the thermal power of the right gas burner 100b is increased. In this case, when the up switch for the right burner 100b is kept on, the thermal power of the right burner 100b increases continuously contrary to the user's expectations. Then, disadvantageously, the cooked material may be excessively heated and the cooking may fail.
Thus, it is an object of the present invention to provide a cooking stove which eliminates the above disadvantages and which prevents the quantity of heat generated by heating means from increasing continuously contrary to the user's expectations, while allowing the user to easily operate the appliance.